Scooters are well known in the art and generally include a platform with a forward wheel and a rear wheel. The forward wheel is pivotally mounted with a pair of handlebars for steering. In a variation on the standard well-known scooter, various types of drives have been adapted to the scooter with an extra wheel and a drive axle added at the rear thereof in order to provide increased stability. In the prior art, one approach to driving these scooters with a mechanical drive teaches the use of a pair of reciprocating treadles, each of which has an end pivotally secured in a fixed position while the other end oscillates in some manner, generally up and down, to drive a crank axle or the like. In some prior art devices, ratchet mechanisms are used to ensure that the vehicle is driven in only the forward direction. One other prior art device eliminates the generally fixed pivotal mounting of the treadle ends and instead mounts those treadle ends with a second, non-functional, crank arm arrangement such that the treadles maintain their generally horizontal orientation to a much greater extent as the treadles are reciprocated. These pedal or treadle powered scooters operate with a pair of rear wheels and are in effect modified tricycles.
Pedal powered two-wheeled scooters are known but only utilize a single pedal or treadle, as exemplified in U.S. Pat. Nos. 4,124,222 or 5,163,696.
The present invention is directed to a pedal powered scooter.
Accordingly, in one aspect of the invention, the invention comprises a scooter having a steerable front wheel assembly, a rear wheel assembly and a frame linking the front and rear wheel assemblies and including a drive mechanism comprising:
(a) a front crankshaft rotatably attached to the frame and comprising a left crank arm and a right crank arm;
(b) a rear crankshaft rotatably attached to the frame and comprising a left crank arm and a right crank arm;
(c) a left pedal comprising a platform rotatably attached to the front left crank arm and the rear left crank arm;
(d) a right pedal comprising a platform rotatably attached to the front right crank arm and the rear right crank arm; and
(e) wherein the front crankshaft transmits power to the rear wheel by means of a front sprocket gear, a continuous chain and a rear sprocket gear.
In one embodiment both the left and right rear crank arms are longer than both of the left and right front crank arms and each of the left and right pedal assemblies has a means for slidably adjusting the length of the pedal. In another embodiment the frame is comprised of a top tube, a trailing arm hingedly attached to the top tube and resilient means disposed between the top tube and the trailing arm with the rear wheel assembly being attached to the trailing arm. The resistance means may be a coil spring. In a further embodiment the steerable front wheel assembly is hingedly attached to the top tube of the frame, allowing the scooter to be folded flat. In another embodiment the rear wheel assembly may be linked to the frame at a point midway between the rear and front crankshafts. In this embodiment two laterally spaced front wheels may be used to increase stability.
In another aspect of the invention, the invention comprises a two-wheeled scooter having a steerable front wheel assembly, a rear wheel assembly and a frame linking the front and rear wheel assemblies and including a drive mechanism comprising:
(a) a front crankshaft rotatably attached to the frame;
(b) a left pedal comprising a platform and a collar attached to a front end of the platform, the collar being attached to the front crankshaft by a freewheel ratchet mechanism;
(c) a right pedal comprising a platform and a collar attached to a front end of the platform, the collar being attached to the front crankshaft by a freewheel ratchet mechanism; and
(d) a seesaw bar pivotally attached to a rear end of the right pedal platform and to a rear end of the left pedal platform, the bar pivotally engaging the frame between the left and right pedals.